Wrench



Nov. 12, 1929.

H. A. MEAD WRENCH Filed May 16. 1929 INVENTOR ,hifLMeaaL QMMgQJJAI;

ATTORNEY Patented Nov. 12, 1929 UNITED STATES PATENT OFFICE HOMER A.HEAD, OF TURLQCK, CALIFORNIA, ASSIGNOR T0 MASTEBE'NOE CORPORA- TION, OFTURLOCK, CALIFORNIA, A CORPORATION WRENCH Application filed May 16,1929. Serial No. 383,426.

This invention relates to improvements in wrenches and particularly toone of that type having a fixed jaw and handle unit and a movable jawpivoted in connection 6 with the fixed jaw, and such as is shown inPatent No. 1,533,602 dated April 14th, 1925, and Patent No. 1,63%,908,dated July 5th, 1927, and issued to myself and E. E. Lynch.

In both these previous devices a spring was employed to return themovable jaw to a closed position adjacent the fixed jaw. These springsare so arranged however that in the wrench of the first mentionedpatent, if the movable jaw was turned to a full open position, the sprinwould disengage the lug provided on the aw and the spring would then beso positioned as to prevent the ready return of said jaw to its closedposition.

In the structure of the second mentioned patent the movable jaw could befully opened and again closed but the spring when fully open would thenbe engaged at such a point in its length as to make it hard for theoperator to move the jaw to such position.

The main object of the present invention therefore is to avoid theobjectionable fea tures of construction of the previous devices byarranging the spring in connection with a specially formed engagingsurface provided therefor on the movable aw in such a manner thatregardless of the extent of opening of said jaw the spring would contactwith said surface at substantially a constant point in the length of thespring at any position of the jaw.

The above object is carried out by means of such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claims.

In the drawings similar characters of reference indicate correspondingparts in the several views:

wrench partly broken out showing the movable jaw closed.

Fig. 2 is a similar v1ew show ng the movable jaw in its fully openposltion.

Referring now more particularly to the characters of reference on thedrawings, the

Fig. 1 is a side elevation of my improved.

numeral 1 denotes the body or shank of the wrench having a handle 2 onone end of the same and a fixed aw portion 3 on the other end; theseelements being a one-piece rigid uni A longitudinal slot 4 is formed insaid unit between the jaw and handle and terminates at onaend adjacentsaid jaw. Projecting into this slot is the shank 5 of the relativelymovable aw 6 which is disposed outwardly of the shank 1 and the fixedjaw; a ivot pin 7 being passed through theshanEs to mount the movablejaw in place for movement in a definite lane relative to the fixed aw.The movab e jaw is wider than its shank and is formed with sideshoulders 8 at its unction with its shank, which shoulders are adaptedwhen the jaw is swung to a fully open position to then aline with andabut against the edges of the shank 1, as in Fig. 2. The total movementof the movable jaw from its fully closed to its fully open position isapproximately 90. The face of the'movable jaw which faces the shank 1and the fixed jaw is so shaped, and the correspondin edges of the shank1 on each side of the s ot are also so formed or shaped relative to thejaw face as shown at 9, that when the movable jaw is in a fully open orspread position, said faces 9 will closely follow and engage four sidesof a hexagonal nut N. The portion of the shank 1 which has said nutengaging faces formed therein may also therefore be considered as aportion of the fixed jaw. With a lesser extent of opening of the movablejaw the nut engaging faces thereof cooperate only with the outer curvedsurface of the jaw 3 beyond the slotto hold a relatively small nut asindicated in dotted lines in Fig. 1. Thus far the structure issubstantially the same as shown in the previous devices alreadypatented.

A flat spring 10 is fastened at one end to the shank 1 at the handle endof the slot 4 and on the same side or ed e of said shank as that fromwhich the mova le jaw rojects. This spring projects through the slotuetween the ad acent end of the slot and the back edge of the movableshank and at its free end enment the compressive pressure is applied tothe spring only at its most flexible oint at all times, and not at apoint approac 'ng its fixed end aswas the case with the device shown inPatent No. 1,634,908 especially. Also the provision of the continuousspring engaging cam avoids the movable jaw then being prevented fromreturning of itself, or with the aid of the spring action, to its closedposition as was the case with the structure shown in PatentNo. 1533,602. 7 v

To further insure the engagement of the sprin with the cam only at alltimes and 'not with the edge of the jaw beyond the cam (which must b geoutwardly as shown at 12, to give the necessary strength to the jawagainst breaking across where it is otherwise weakened by the nutengaging faces being out into the same) the spring between its ends isconvexly curved relative to such bulging surface so as to avoid contactwith the same even when the movable aw is fully opened and partlydepends into the slot immediately ahead of the spring, as shown in Fig.2.

From the foregoing description it will be readily seen that 'I haveroduced such a device as substantially ful s the objects of theinvention as set forth herein.

While this s ecification sets forth in detail the present and preferredconstruction of the devlce, still in practice such deviations from suchdetail mdy be resorted to as do not form a departure from the'spirt ofthe invention, as defined by the appended claims.

Having t us described my invention what I claim as new and useful anddesire to secure by Letters Patent is:

1. A wrench including a handle shank having a fixed'jaw on one end and alongitudinal slot adjacent the jaw, a shank projecting into the slot, apivot pin through both shanks, a jawon the pivoted shank outwardly ofthe slot, said pivoted shank and jaw being arranged for substantially 90of arcuate movement relative to the handle shank, a flat spring memberprojecting through the slot beyond the pivoted shank and fixed at oneend to the handle shank on the same side thereof as that from which themovable jaw pro: jects, and a cam surface formed on the adjacent edge ofthe movable shank disposed relative to the shank pivot so as to engagethe spring at substantially a constant point and ad acent the outer endof the latter throughextent of openin the pivoted shank and fixed at oneend to the handle shank on the same side thereof as thatfrom which themovable jaw projects, and a cam surface formed on the adjacent edge ofthe movable shank for engagement with the spring and so disposedrelative to the pivot pin and to the s ring as to cause the spring to beincreasing y compressed between the closed and open positions of themovable-jaw while maintaining the s ring engaged with the cam at aconstant pomt in thelength of the latter.

3. A structure as in claim 2, in which the spring, intermediate itsends, is shaped to avoid contact with the back edge of the movable shankbeyond the cam irres ective of the g movement 0 the movable shank andaw.

In testimony whereof I afiix my leigpature.

HOMER A.

